Re: Don't Kick Harder!
cjborgert said:
No, No, No. . . sorry that I gave an ambiguous suggestion . . .my comment was meant to explain that there are other reasons to freedive with long blade fins other than purely for efficiency.
"efficiency" can be an ambiguous word and requires to be defined... it depends on the goal...
in static apnea "efficiency" is the time you spent underwater...
in dynamic apnea "efficiency" is the length you swim underwater (and not the time)
cjborgert said:
Now, at dynamic apnea depths, negative buoyancy is not the issue, but speed is . . .
this not at all obvious !!! the target in dynamic apnea is not the speed, but the length...
the winner is not the first arrived, but the one who swims the longest distance underwater, disregarding of the time spent...
on the 12th of March, I could admire Stephane Mifsud doing 175 m in dynamic apnea ; he had bi-fins and it took him as long as 3'44" (approx. 30"per 25 m), which was very slow...
with a monofin, you swim approx. twice as quickly as with bi-fins, but you burn twice as much oxygen as with bi-fins ;
the monofin eliminated completely the bi-fins in finswimming because in this sport "efficiency" means speed... in apnea, it is not so obvious precisely because speed is not the target...
cjborgert said:
and long blades can increase your speed more rapidly than other fins . . .by displacing more water with each kick. . .
in your post you talked about the GEOMETRICAL DIMENSIONS of the fins but you forgot extremely important parameters : the STIFFNESS (static, dynamic or "response") and the MECHANICAL properties....
you forgot to talk about ENERGY spent with each kick....